files/en-us/web/api/vrdisplay/requestanimationframe/index.md
{{APIRef("WebVR API")}}{{Deprecated_Header}}{{Non-standard_Header}}
The requestAnimationFrame() method of the {{domxref("VRDisplay")}} interface is a special implementation of {{domxref("Window.requestAnimationFrame")}} containing a callback function that will be called every time a new frame of the VRDisplay presentation is rendered:
[!NOTE] This method was part of the old WebVR API. It has been superseded by the WebXR Device API.
VRDisplay is not presenting a scene, this is functionally equivalent to {{domxref("Window.requestAnimationFrame")}}.VRDisplay is presenting, the callback is called at its native refresh rate.requestAnimationFrame(callback)
callback
VRDisplay presentation is rendered.A long representing the handle of the requestAnimationFrame() call. This can then be passed to a {{domxref("VRDisplay.cancelAnimationFrame()")}} call to unregister the callback.
const frameData = new VRFrameData();
let vrDisplay;
navigator.getVRDisplays().then((displays) => {
vrDisplay = displays[0];
console.log("Display found");
// Starting the presentation when the button is clicked: It can only be called in response to a user gesture
btn.addEventListener("click", () => {
vrDisplay.requestPresent([{ source: canvas }]).then(() => {
drawVRScene();
});
});
});
// WebVR: Draw the scene for the WebVR display.
function drawVRScene() {
// WebVR: Request the next frame of the animation
vrSceneFrame = vrDisplay.requestAnimationFrame(drawVRScene);
// Populate frameData with the data of the next frame to display
vrDisplay.getFrameData(frameData);
// You can get the position, orientation, etc. of the display from the current frame's pose
const curFramePose = frameData.pose;
const curPos = curFramePose.position;
const curOrient = curFramePose.orientation;
// Clear the canvas before we start drawing on it.
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
// WebVR: Create the required projection and view matrix locations needed
// for passing into the uniformMatrix4fv methods below
const projectionMatrixLocation = gl.getUniformLocation(
shaderProgram,
"projMatrix",
);
const viewMatrixLocation = gl.getUniformLocation(shaderProgram, "viewMatrix");
// WebVR: Render the left eye's view to the left half of the canvas
gl.viewport(0, 0, canvas.width * 0.5, canvas.height);
gl.uniformMatrix4fv(
projectionMatrixLocation,
false,
frameData.leftProjectionMatrix,
);
gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.leftViewMatrix);
drawGeometry();
// WebVR: Render the right eye's view to the right half of the canvas
gl.viewport(canvas.width * 0.5, 0, canvas.width * 0.5, canvas.height);
gl.uniformMatrix4fv(
projectionMatrixLocation,
false,
frameData.rightProjectionMatrix,
);
gl.uniformMatrix4fv(viewMatrixLocation, false, frameData.rightViewMatrix);
drawGeometry();
function drawGeometry() {
// draw the view for each eye
}
// …
// WebVR: Indicate that we are ready to present the rendered frame to the VR display
vrDisplay.submitFrame();
}
[!NOTE] You can see this complete code at raw-webgl-example.
This method was part of the old WebVR API that has been superseded by the WebXR Device API. It is no longer on track to becoming a standard.
Until all browsers have implemented the new WebXR APIs, it is recommended to rely on frameworks, like A-Frame, Babylon.js, or Three.js, or a polyfill, to develop WebXR applications that will work across all browsers. Read Meta's Porting from WebVR to WebXR guide for more information.
{{Compat}}